Id say got a truck bed fuel tank. i got a friend who has one and the thing is great, when you have about 10 gallons in it it doesnt move at all if you have a bed liner so you can also freely take it out to reduce weight when you dont need it. Just my $.02 for you

I have a 2012 Sierra 1500 W/T with the standard cab/8 foot bed and it came with a 36 gallon tank. I know the non work trucks have a smaller tank. I can't see why the tank from a 1500 work truck wouldn't fit the other trucks.